Concrete products manufacturer Rocla has added the Alfabloc precast concreteretaining wall system to its range of products. Rocla sales engineer Justin Kretzmar says that, while the Alfabloc system, which is new to the country, has not yet been used on any rail infrastructure projects, there is potential for it to be used by the rail sector.
Rocla recently acquired the exclusive product distribution licence for Southern Africa for these precast retaining wall systems. Alfablocs can be used as security and safety options for railway lines.
The A-frame design of the Alfabloc makes it structurally efficient and versatile for rail applications, as it features a hollow cavity, which reduces weight and provides a secure medium in which to run cables.
“Keeping people away from the railway lines is a major problem in South Africa. The Alfabloc serves as a barrier to keep people away from railway lines and out of harm’s way,” he says.
The product’s constant slope makes it difficult to climb over and threaded inserts on top provide for the attachment of additional and higher elements, such as electric fencing or barbed wire, to be added. Alfabloc comes in heights of 1.2 m, 2.4 m, 3 m and 3.6 m and features a cast-in-concrete tongue-and-groove joint that enables the blocks to interlock, thereby forming a solid wall.
Further, the company also supplies tractional masts and rectangular culverts to the rail industry. Rocla designs the tractional masts specifically for railway overhead track equipment (OHTE) to ensure limited deflection or bending under heavy loads.
“These masts are capable of handling high loads and come in lengths of 9 m, 11 m, 12 m and 13 m, with strength ratings of either 64 kNm or 84 kNm. These concrete masts are suitable for long-term OHTE structures, which do not need to be maintained and are not affected by natural elements, vandalism or rust,” says Kretzmar.
All masts have a required planting depth, which can then be backfilled with moist, compact soil. In addition, they are designed to the specification of clients and no drilling is necessary, as the masts can be manufactured with preformed holes to attach cables.
The poles are resistant to rust and rot and have no scrap value, eliminating the chance of theft.
Rocla has a range of culverts specifically designed for use in rail stormwater drainage applications and provide a waterway underneath a railway line. The culverts can also be used in any application where excessive fills need to be accommodated.
These products are used at crossings to enable waterto move from one side of the crossing to the other. The units comprise a deck and two legs and are placed on concrete bases, which can be cast on site or prefabricated.
Owing to time constraints, a precast concrete slab base is sometimes more economical than bases that are cast on site. Culverts are supplied in standard lengths and strength classes but these can be adjusted to meet the needs of the client.